1. Field of the Invention
The system and method of the present invention relates to cleaning of tanks. More particularly, the present invention relates to a system of cleaning solids and liquids which have accumulated in tanks, particularly of the type for collection of residue from a downhole drilling operation, wherein the solids in the tank care excavated through high pressure/high volume fluid injection, and are retrieved from the tank while the tank continues to be in operation under high pressure or low pressure (1440 psi--ambient) while the tank remains closed and sealed.
2. General Background
In the drilling and production of oil, the production platform includes all offshore or land production vessels, which receive the salt water, oil and gas condensate and sand, from the downhole production, for collection in the tank. However, during collection, the tank, over time, will accumulate a great quantity of solid materials such as sand, paraffin and other solids, which collect within the tank, and although the fluids such as the oil and water may be siphoned from the tank, the solids which accumulate often fill the entire tank, which after awhile, must be cleaned from the tank in order for the tank to be usable or function at full capacity. Currently, in order to do this, production must be shut off to the vessel or vessels to be cleaned on a platform, and the platform must be shut down, perhaps for days at a time, while the solids are being removed from the tank, to return it into use. If, for example, a platform is producing 10,000 to 30,000 barrels of oil a day, one can imagine the considerable cost of having to shut the platform down and the loss of revenues involved while this operation is going forward, even if there is a temporary loss of production. Also, current methods of cleaning involve cleaning manually with trained personnel making a "confined space entry" which can be dangerous, considering toxic components sometimes are present in the vessels. Most of the time, the vessel is entered through a man-way hatch, but cannot be entered in any other opening to the vessel. Therefore, there is a need in the industry for a system and a method for cleaning the tanks on a platform, whereby the solid materials which have accumulated in the tank can be cleaned while the tank continues to be in operation under high pressure, and there is little or no time lost during the cleaning process.